Improvement in the manufacture of sheet-metal tubing



S. R. WILM-T. Manufacture Uf Sheet Metal Tubing.V

Patented Apri115,1873,

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AM PuoTo-L/mc/eAPH/c co, Ilmosaorwf's moms) 2 Sheets--Sheet 2.

S. R. W|LMOT.

Manufacture of Sheet Metal Tubing.

Patented April i5, 1873.

AMPHom-umaGHAP/llc co, m'fossofm manges.)

To all whom it may concern:

. llongitudinal vertical section on the line a a of fthe same. Fig. 3 is a plan of the core or male former. with attached devices for aiding in transverse section on the line a3 a3' Fi 8 a 'raras UNITED ATENT FFICE.

SAMUEL It. WILMOT, OF BRIDGEPORT, CNNECTIT.

Specification forming part of Letters Patent No. 137,999, dated April 15, 18723; application filed March 1, 1873.

Be it known that I, SAMUEL RUssnLL Wu.A MOT, of Bridgeport, in the county of Fairfield and State of Connecticut, have invented certain Improvements in the Manufacture of Metal Tubing, of which thefollowing is a specification:

This invention generally consists in an or ganized system of devices, including guides, formers, and dies, whereby on draft, as distinguished from thrust, being applied to a strip of sheet metal the latter is bent into tubular form and its edges turned to constitute a locked seam, and such seam not only closed, but firmly compacted or compressed in every direction in common with the whole circumferential portion of the tube, both inside and out, by the drawing of the tube, as the seam is closed, through a finishing-die, thus pro-` ducing a die-drawn locked-seam tube, which is smooth externally and internally, and may be made of greater length and thinner or lighter and stronger than any locked-seam tube heretofore produced by means of rolls.

In the accompanying drawing, which forms part of this specification, Figure 1 represents a plan of an apparatus or combination of de vices embodying my invention, and Fig. 2 a

shaping, seaming, closing, and drawing or nishing the tube. Fig. 4 is a side view of the same; Fig. 5, a transverse section thereof on the line a1 al, showing also the female former in relation therewith; Fig. 6, a transverse section on the line c2 a2 of like parts; Fig. 7, a

transverse section, upon a larger scale, on the line a a4,- and Fig. 9, a transverse section, upL onthe 'same scale as in Fig. 8, on the line a5 a5. Fig. 10 is a transverse section of the strip of sheet metal immediately previous to its entry beneath the core or male former, as indicated by the line b b in Fig. 3 5 Fig. 11, a transverse section of the same when partly bent as on reaching a position under the malecore or former indicated by the line bl b1; Fig. 12, a transverse section thereof, showing the shape it assumeswhen reaching the line b2 b2; Fig. 13, a transverse section thereof at the. position indicated by the line b3 b3; Fig. 14, a transverse section at the position denoted by the line b4 b4,- -Fig. 15, a transverse sect-ion at the position indie. ted by the line b5 b5; and Fig. 16, a similar section to Fig. 15, but on a larger scale. Fig. 17 ,is an inverted plan of a tongue used to form the seam.

Similar letters of reference indicate correspondin g parts.

A is a strip of sheet metal of any desired length, width, and thickness, according to the strength and size of the tubing to be made. This strip. may either-be brass, copper, steel, or any other suitable metal, and may be rolled upon a reel, B, for supply to the tube-forming devices, or be otherwise suitably fed. From the reel B the strip A of metal passes under a cross guide, bar, or roller, c, down within and along a trough, C, between adjustable side guides or wings lD that serve to direct the strip to its proper position beneath the core or male former E, and between the latter and a correspondingly-shaped female former, F, subject to the action or pressure of a calnlever or other suitable clamp, Gr, which, bearing down on the male formerE, serves to pinch or keep the strip A from buckling or crinkling while being drawn through between the two formers. Said formers E and F are of tapering width, diminishingl towardtheir forward ends, and the trough B maybe of acorresponding taper. In addition tov such construction of said formers, their contiguous surfaces, which bear upon the strip A, are of a gentle curvature at their rear endsfand a gradually-quickening curvature toward their forward ends, to produce a gradual bend of the strip into a tubular or partly-circular form as it is drawn forward between the formers E and F.

The strip A is drawn forward and through the dies in front of the formers by first cutting a tongue or tapering extension on the front of the strip and passing it through in front of the apparatus, so that it may be readily taken hold of by a pair of power-pinchers or othera wise, and so form a handle or hold whereby to draw the' remainder of the strip through the apparatus, suc-h handle portion afterward bea ingb cut off as waste from the one end of the tu e.

. v0u the top of the male core or former E is a plate, d, the edges of which overlap the body or shaping portion of said former, as clearly shown in Figs. 5 and 6, and also lie over or overlap the upper edges of the female former F to guide the edges of the bent strip and insure thev smoothand straight or steady draft of the strip between the formers to the dies free from any bruising or marrin g of the edges of the strip. The male core or former E may be removable by sliding it backward on releasing the clamp G, and when in position is retained in Y place, together with its attachments, which enter the dies in front, and the same prevent ed from being drawn unduly forward on heavy draft being applied to the strip by a stop suitably applied at any desired point to said former E; as, for instance, by a lip or projec- Ition,`e, on an attached front extension or sec tion, arranged to enter a recess in the upper portion of the closing-die H. This closingdie H is ofa closed circular forln in its transgverse section,'but of a gradual taper in direc` tion of its length, reducing in diameter forwardly'that is, in thedirection the strip` travels or is drawn. Arranged to fit concentrically within this die is a correspondinglyvtaperin g forward extension ot' the core or male former E, which extension is preferably constructed in sections f g h t', the two latter sections, h e', as also an advance ring or mandrel, k, fitting as sleeves over a central shank, Z, ofthe section f, and being retained in place by a nut, m, on the outer or forward end of said shank. The section g fits as a top or cover and virtually forms part of the section f, and has attached to it, by a dovetail-lock or otherwise, a tongue, n, which lies within a curved tapering groove, o, in the upper surface of the section h; but, or for the most of its forward portion, is free from contact there- 'with to allow of the underlapping portion of 'the seam inthe tubing as the latter is closed,

-passing under the tongue, the edges of the ,strip of which the tubing is composed having been previously bent to lock the one. with the -other by their .travel along grooves fr r in the upper surface of the top g, vand beneath a tapering upper part of said top or cover, and by their continued travel along or past the tongue n; This tongue forms a close fit on its upper 'surface with the interior of the die H, which sustains it against being strained or broken .by the passing strip or partially formed tubing. The top g or upper part of the section f may also be similarly supported by the die H. The tongue a is grooved along its one side, in continuation of the groove 1^, in the piece g, subject to interruption by a jog or rise, u, which turns the one edge, c, Fig. 13, of the strip inward, while the other side of the tongue is made with an overhanging portion, fw, at the root of the tongue. The section i has a groove, s, in its upper surface for the passage of the closed seam of the tubing out of the groove 0 through it, and the manlows: As the strip A is drawn between the formersE F and out through the dies H I, it, on reaching the position shown by dotted line b1 in Fig. 3, is curved, as represented in Fig. 11, and on reaching the dotted line b2 is further bent, as in Fig. 12. After this, and when the strip passes within the die H, which gradually causes the edges of the strip to approach and give tothe strip its required tubular shape, said edges pass within the grooves r r and along the grooved and recessed sides of the tongue n, and, on reaching the position represented by dottcd line, b3, are bent as represented in Fig. 13, the one edge, o, being bent inward by its passage over the jog u, while the other edge is shaped, as represented in Fig. 13, by its passage under the wing w of the tongue a. The further passage ofthe strip to the position represented by dotted line, b4, causes the edge o to be further slightly hooked or bent by the combined action of thedie H and the groove in the side of the tongue a, while the other edge of the strip, byits passage under the forward portion of said tongue, and transversely within as well as along the groove o, is bent by said parts in combination with the tapering die H, to pass under and into engagin g position with the first-mentionedl edge, as represented in Fig. fam s said strip A further moves toward the ront and narrower or closing end ofthe die H, the engagment or hooking together of the two edges is completed by the action of the forward portion of the groove o and surrounding portion of the die on the edge which passed under the tongue, so that when the seam enters the groove s in the section i the same is closed by the die H. The seam having been thus closed or locked, the strip assumes the shape of a locked seamed tube, as represented in Figs. 15 and 16, but is not yet materially drawn or nished. To complete it or make of it a perfect die-drawn lockedseam tube, the closed tube, as it leaves the tapering die H and tapering core-sections f It and i, is drawn through the finishing cylindrical die I and around the cylindrical man drel or core k, having the groove s in it for accommodation of the seam. This produces a drawing action on the tube, and compresses or compacts the seam, not only as regards its faces or above and below, but edgewise, or in every direction, and simultaneously compacts or compresses the whole body of the tube cir cumferentially, both inside and out, as it passes throughv or from out of the die i.

If preferred, the strip A may be introduced to the apparatus in a partly-curved form instead of in a flat shape.. Likewise the forniers, dies, and accompanying devices may be constructed to produce a lluted tube, also, if desired, to throw the seam outward instead of inward without departing from the principle that distinguishes my .invention from other devices heretofore used to produce a lockedseam tube.

In some cases the drawing-die I and its core 7c may be omitted hd the locked seam produced by the closingfdie IEE-and its core be h'ermetica-lly sealed by brazing or not,"accord ing to circumstances or other purposes for whichthe tubes are required.

Wha-t is here claimed, and desired to be secured by Letters Patent, isy As an improvement in the art of mannfacturing tubing of sheet-metal strips or skelps with interlocked joint or seam, the method of condensing and consolidating the joint or seam, and also the metal of the tubeproper, by drawing the same through a die or dies that impinge against, compress, consolidate, and draw upon, all the exposed surfaces of Vthe joint or seam, and of the tube itself, subtantially as described.

2. An improved machine, constructed substantially as described, of formers, guides, and dies, organized, so that as a strip of metal is drawn therethrough or between the same, to bend said strip into a tubular form, to turn its edges to interlock one with another, to close the seam thus produced, and to die-draw such locked-seam tube by pressure applied in every direction both to the seam and body of the tube circumferentially, inside and out.

3. The combination of the male former E and its overhanging plate or portion d with the female former F, and the tapering circular closing die H with its tapering core or eX- tension of the male former E, essentially as herein set forth.

4. The combination with the tapering die H of the tapering section or portion f, having grooves r r arranged to converge in a for Wardly direction, substantially as speciied.

5. The grooved tongue fn, wing w, and jog u, in combination with the groove o in the section or portion h of the core, and the closing die H, essentially as described.

6. The combination, with the elements recited in the last preceding clause of claim, of the drawing-die I and its grooved core k, substantially as specified.

7. The sectionally-constructed core or core extension, composed of detachable sections j' g hi and k, arranged in relation with each other and with the dies H I, essentially as described.

8. The detachable male former E, with its attached core Vor forward extension, in coni bination with a stop, e, arranged to resist the draft on `said former E relatively to the tapering die H, substantially as specified.

Witnesses:

MICHAEL RYAN, A. GREGORY. 

